The present invention relates to a new washing process and a washing apparatus suitable to washing clothes, tableware, medical equipments and washing hands, etc.
Surfactant, such as chemicals and soup, has been heretofore been used for washing clothes, tableware, medical equipment, toilets, etc., however, there have been problems of causing chapping hands when washing, a safety issue on body by residual detergent on washing items, and residual harmful substances after a treatment of discharging water, etc.
Inventors of the present invention proposed a method of washing washing items while softening washing water containing at least one of carbonate ion or bicarbonate ion and alkali metal ion (refer to PCT/JP99/00242, WO99/37414). This directs attention to the fact that a composite generated at the time of softening a solution containing alkali metal ion and carbonate ion and/or bicarbonate ion realizes cleansing effect and adsorption effect, which shows detergency comparable to or more excellent than the conventional detergent such as surfactant and becomes human body-friendly and environment-friendly.
However, when trying to produce a solution containing alkali metal ion and carbonate ion and/or bicarbonate ion as an undiluted detergent it is necessary to use as its material a substance having a problem on handle ability such as sodium hydroxide, thus there has been a problem to carry out at home from producing detergent to washing.
The present invention has as an object thereof to provide a method of enabling to produce detergent only by substances superior in being handled and an apparatus therefor.
(1) According to a first aspect of the present invention, a method of producing detergent includes a step of electrolyzing a solution containing at least one of carbonate and bicarbonate of alkali metal.
Namely, as shown in FIG. 1, by making a solution of a substance containing at least one of carbonate and bicarbonate of alkali metal (see Step 1 to 2 in FIG. 1) and by electrolyzing the solution (see Step 3 in FIG. 1), an undiluted detergent can be obtained (see Step 4 in FIG. 1).
By electrolyzing a solution containing at least one of carbonate and bicarbonate of alkali metal, for example, a solution of substances superior in handle ability such as sodium carbonate, potassium carbonate, lithium carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate, as a solution to be electrolyzed, it is possible to obtain an undiluted detergent containing alkali metal ion and carbonate ion and/or bicarbonate ion, and by washing as softening the same, it shows detergency comparable to or better than the conventional detergent, such as surfactant, and becomes human body-friendly and environment-friendly. Accordingly, a series of procedures from producing detergency to washing can be realized at home.
As alkali metal carbonate according to the present invention, for example, sodium carbonate Na2CO3, potassium carbonate K2CO3, lithium carbonate Li2CO3, etc. can be listed, while as alkali metal bicarbonate, for example, potassium hydrogen carbonate KHCO3, sodium hydrogen carbonate NaHCO3, etc. can be listed.
Also, when making a solution of carbonate or bicarbonate of alkali metal, a variety of kinds of water may be used, such as tap water, well water, soft water, refined water, pure water, or mixed water of these, etc.
(2) Although, it is often the case that a pH, etc. of detergent to be used differ in accordance with a property of washing items, in the present invention, when producing detergent by electrolyzing a solution containing at least one of carbonate and bicarbonate of alkali metal, it is possible to adopt forms below in accordance with an aimed potential of hydrogen (pH=6 to 12) of the detergent.
As a first embodiment, cathode water or anode water obtained by electrolyzing by supplying the above solution to be electrolyzed at least to an anode chamber of an electrolyzing cell having a cathode chamber and an anode chamber separated by a diaphragm can be used as an undiluted detergent (see FIG. 4A). The cathode water obtained by this form becomes an alkaline undiluted detergent having a high pH.
In this case, as a second embodiment, when cathode water obtained by electrolyzing by supplying the above solution to be electrolyzed to both of the anode chamber and the cathode chamber of the electrolyzing cell having a cathode chamber and an anode chamber separated by a diaphragm is used as an undiluted detergent, it is possible to obtain a highly concentrated undiluted detergent wherein rising of the pH is suppressed (see FIG. 4B).
Also, as a third embodiment, cathode water or anode water obtained by electrolyzing by supplying the above solution to be electrolyzed at least to an anode chamber of an electrolyzing cell having a cathode chamber and an anode chamber separated by a diaphragm or mixture of the both water is further added and dissolved at least one of carbonate and bicarbonate of alkali metal after completing the electrolysis and thus obtained solution can be used as an undiluted detergent (see FIG. 4C).
Furthermore, as a fourth embodiment, by electrolyzing by supplying the above solution to be electrolyzed at least to an anode chamber of an electrolyzing cell having a cathode chamber and an anode chamber separated by a diaphragm, and mixing the obtained cathode water or anode water after the electrolysis is completed, the thus obtained solution can be used as an undiluted detergent (see FIG. 4D).
In this case, as a fifth embodiment, it is also possible to use as an undiluted detergent mixture of cathode water or anode water obtained by electrolyzing by supplying the solution to be electrolyzed to both of the anode chamber and the cathode chamber of the electrolyzing cell having a cathode chamber and an anode chamber separated by a diaphragm (see FIG. 4E).
In the fourth and fifth embodiments, since the mixture of the anode water and the cathode water becomes an undiluted detergent, a production amount of the obtained undiluted detergent becomes doubled, or otherwise, the capacity of the electrolysis cell can be halved.
The cathode water in the first embodiment, the cathode water in the second embodiment, the cathode water in the third embodiment, the mixed water in the fourth embodiment and the mixed water in the fifth embodiment have a pH of 9.5 to 12.0 and can be used as an alkaline undiluted detergent.
On the other hand, the anode water in the first embodiment and the anode water in the third embodiment have a pH of 6 to 8 and can be used as a neutral undiluted detergent.
In a method of producing detergent of the present invention, the pH and electric conductivity can be easily adjusted by suitably setting the conditions of electrolysis.
(3) The above undiluted detergent can be used for washing as it is or diluted (see Step 5 to 6 in FIG. 1. Hereinafter, also referred to as a diluted detergent A). An electric conductivity of the diluted detergent is 100 mS/m or more, preferably, 150 mS/m or more.
Also, a variety of washing aid agents for improving detergency, etc. can be added (see Step 9 in FIG. 1).
Namely, the above alkaline detergent can be added fatty acid or soap, such as oleic acid or oleic acid potassium, at the time of or after being diluted by water, to be used as detergent.
Also, the above neutral detergent can be added a variety of washing aid agents to be used as detergent, such as antisoil redeposition (for example, carboxyl methyl cellulose), nonionic surfactant (for example, sugar fatty acid ester, polyoxyethylene sorbitan fatty acid ester), dispersing agents (for example, carboxyl methyl cellulose) and water softening agents (for example, EDTA, citric acid).
Auxiliary/aid agents used in the present invention are emulsifier (surfactant) used for food processing and gum/thickening agent as food additives, and by not using the conventional surfactant for washing, safer detergent can be provided. Furthermore, since the detergency is given to the electrolytic water obtained by electrolysis of a solution of alkali metal carbonate/bicarbonate, the surfactant can be made to be minimum thickness required for antisoil redeposition, and it becomes possible to reduce a burden on an environment by suppressing usage of organic substances.
(4) Note that the present invention may include a step of softening the detergent containing at least one of carbonate ion and bicarbonate ion and alkali metal ion, particularly the above undiluted detergent or the diluted detergent A (see Steps 7 to 8. Hereinafter, the obtained detergent will be also referred to as diluted detergent B).
In this case, it is preferable to adopt a means to make it contact solid carbonate composite which is water-insoluble or hard to be dissolved in water.
(5) Further, according to a second aspect of the present invention, an electrolysis cell wherein an anode chamber and a cathode chamber are separated by a diaphragm, a solution tank for making a solution by dissolving at least carbonate or bicarbonate of alkali metal in water, a detergent producing apparatus having a first supply means for supplying the solution in the solution tank at least to the anode chamber of the electrolysis cell and a mixing means for mixing anode water and cathode water respectively generated in the anode chamber and the cathode chamber to make mixed electrolytic water after completion of the electrolysis are provided.
In this case, preferably, the mixing means comprises a water tank for storing anode water and cathode water after completion of the electrolysis and a second-supply means for supplying the anode water and cathode water generated in said anode chamber and cathode chamber to said water tank.
Also, there is provided a detergent producing apparatus, comprising an electrolysis cell wherein an anode chamber and a cathode chamber separated by a diaphragm, a solution tank for making a solution by dissolving at least one of carbonate and bicarbonate of alkali metal in water, a first supply means for supplying the solution in said solution tank at least to the anode chamber of said electrolysis cell, a detergent tank for storing detergent discharged from said electrolysis cell, and a third supply means for supplying one of cathode water after completing the electrolysis generated in said cathode chamber and anode water after completing the electrolysis generated in said anode chamber to said detergent tank.
In this case, it is preferable to comprise a means for adding and dissolving at least one of carbonate and bicarbonate of alkali metal to at least one of anode water generated in said anode chamber and cathode water generated in said cathode chamber.
(6) According to a third aspect of the present invention, there is provided a washing machine comprising a detergent producing apparatus for producing detergent by electrolyzing a solution containing at least one of carbonate and bicarbonate of alkali metal; a detergent tank for storing said detergent; a washing tub for washing; a means for supplying diluting water of said detergent to said washing tub; and a means for supplying said detergent from said detergent tank to said washing tub.
In this case, it is preferable to further comprises a judgement means for judging an amount of washing items and/or an amount of washing water in said washing tub and a setting means for setting the amount of washing items and the amount of washing water; and a control means for outputting to said detergent supply means a control signal for supplying the washing tub an appropriate amount of detergent for washing based on an output signal from said judgement means or said setting means.
Furthermore, it is preferable to comprise a container for storing washing aid agents, a means for supplying washing aid agents from said container to said washing tub, and a control means for outputting to said supply means of washing aid agent a control signal for supplying an appropriate amount of the washing aid agents for washing to the washing tub.
(7) The above detergent producing apparatus or washing apparatus can be applied to a washing machine, dish washer, etc.